Although citrus trees like soil on the moist side, excessive rain over overwatering to the point where soil remains soggy, can cause root rot. Droopy foliage is one of the symptoms of root stress. The roots need oxygen as well as moisture and if you water too much, the roots will suffocate. Taper off on watering and see if that doesn't help the situation. I hope it does. Citrus should be fed in March, June and September so if you haven't fed your trees, be sure to feed them this spring. Enjoy your landscape!